BayesFusion Support Forum

Thanks Martijn

Hi

I have unrolled my DBN to 5 time slices. I have entered evidences for the 5 time slices and performed the inference using the Polytree algorithm. Is the inference considered Filtering in this case P(Xt|y1:t)?

Regards

Thank you shooltz

Thanks Martijn

regarding my question "does the B1 of murphy defined implicitly when unrolling the network". I mean murphy has defined the DBN as a pair of (B,B'), where B represent the initial network (static bayesian network at time t=1). while B' is a two time slice temporal bayesin network. I ...

Hi
Sorry for asking too much but really reading around made me confused.

I just found the master thesis "Modelling Physiological processes with DBN" by J. Hulst, I have read it and understood that in GeNIe, the DBN is defined as follows:

P(Zt|Zt-1....Zt-k)= *i=1-n P(Zit|Pa(Zit)). this in page 54 ...

hi
can i have any documentation on how the polytree working with the rolled up network?

Regards

Thank you for all help, i have understood now the differences between the algorithms and can justify my work correctly.

Regards

the most important thing that the results is the same. i will keep my work as it is instead remove that " we consider our DBN as a pair of (B,B1) from the discription and say we unroll the network and perform the polytree algorithm.

yes i have read this thesis. so you mean in the case i have mentioned (murphy), the network will work in the way i described but in your case is totally different?

and in this case my DBN is cosidered as a pair of (B,B1):

where B is the static bayesian network that defines P(Z1)
and B1 is a two slices TBN that defines P(Zt|Zt-1)

Is that correct?

thank you for your support.

Regards

Hi
thanks alot for your help

i have unrolled the network and i have understand that at time 0 the hypothesis node will affect by contextual and variavle information only while in time slice 1 it will affect by the contextual and observable variable as well as the hypothesis node at the previous ...

is the first order temporal arc means that the relationship between two time slices modeled by first order hidden markov model. thats what made me confused

just want to understand how the network will take into account the hypothesis node at the previous time slice during infering the hypothesis node at current time slice

thank you very much for your help
i really like the software and your support

I have read that the inference in DBN can be done by either considering the unrolled network as exactly as static network and we can perform polytree or converting the network to a HMM and perform forward backward. In this case i have to say that we consider the dynamic network as unrolled static ...